第29题: [单项选择]Conversation Two A. Because it may improve the working staff’s literacy. B. Because it may help improve the productivity. C. Because it kills the spare time of the working staff. D. Because it helps make a good working environment. 参考答案:B 答案解析:[听力原文] Q: According to Peter, why book reading is important for business
第31题:[多选题] 直流系统发生正极或负极接地时,对运行有什么危害? A. 直流系统发生正极接地时,有可能造成保护误动 B. 因为电磁机构的跳闸线圈通常都接于电源负极一端,倘若回路再发生接地或绝缘不良就会引起保护误动作。 C. 直流系统负极接地时,如果回路中再有一点接地时,就可能使跳闸或合闸回路短路,造成保护装置和断路器拒动, D. 烧坏继电器,造成熔断器熔断。 参考答案:ABCD